The invention relates to a pharmaceutical preparation that contains at least one pharmaceutically active substance (excluding ibuprofen), especially an insoluble or a slowly or sparingly soluble active substance, at least one granular carrier material, and a layer enveloping the carrier material that contains other components.
In the manufacture of pharmaceutical preparations of solid active substances for oral administration, the active substance is usually mixed with flavor-improving filler materials and possibly coloring and/or aromatic substances. Various inactive ingredients such as protective colloids, disintegrating agents (hereinafter "disintegrants") and the like may also be added. If necessary, the preparation is granulated, reduced to the desired grain size, and then pressed into tablets. The tablets are than sugar-coated. Even with the best possible mixing action, in these tablets, the active substance is present in randomized form.
In recent times, it is increasingly becoming widespread to advise that many medicines be taken with a large amount of water, especially when the dosage to be administered is large, e.g., 1,000 mg of an active substance per administration. It is therefore often attempted to make the preparations in the form of instant powders or tablets, or in the form of effervescent powders or tablets, which prior to being administered are dissolved or suspended in water with or without formation of carbonic acid.
The absorption of active substances by the human body is a problem of distribution. If active substances that are present in small amounts are to be administered to the body optimally, then it is expedient to dilute such substances in advance or to dissolve them, since the surface of the active substance available for the absorption by the body is enlarged or better utilized. For example, ferrous gluconate, if it were not dissolved in water, would attack the mucous membrane of the stomach and cause side effects.
In the case of antibiotics, or of all water-insoluble substances, for example, in order to be absorbed more easily the substance should be suspended in water in the finest form.
In the manufacture of instant powders or tablets from insoluble or sparingly soluble active substances which are bitter tasting in water, the most diverse problems are encountered. On the one hand, due to the different grain sizes of the individual components of the mixture, it is often difficult to apportion the components precisely. On the other hand, when using freely soluble sugars (for the purpose of improving the flavor), the tablets decompose only very slowly in spite of the use of disintegrants because the concentrated sugar solution forming on the surface clogs the capillaries of the distintegrants, thereby disrupting or at least strongly retarding its effect.